German Patent Application DE 44 43 849 A1 describes a push rod which is eccentrically mounted to a motor and is thus capable of automatically opening the washing tub door to an ajar position after completion of the wash and rinse cycles, allowing the residual moisture to escape by natural convection. Although the opening mechanism described in that publication improves the drying process, problems still arise because the described opening mechanism allows an opening gap of only ten millimeters. A longer opening stroke is advantageous especially when the dishwasher is integrated into a row of kitchen units and covered on top by a countertop. In the design described in DE 44 43 849 A1, the warm, moisture-laden air condenses on the underside of the cold countertop, which may result in damage thereto.
DE 10 2006 054 414 B3 describes a door with a door lock for engagement of a latch keeper.
European Patent Application EP 0 687 439 A1 describes a dishwasher in which the door is likewise opened to an ajar position after completion of the wash and rinse cycles by means of a latch keeper that can be displaced by motor means. Here, the latch keeper remains in this slightly open position after the end of the cycle. As a result, it should be easier for the user to close the door after unloading the appliance because the push rod is then pulled to its end position by the motor. A disadvantage of this approach is that the opening gap has to be large during assisted drying (see above) and, therefore, the latch keeper protrudes far into the room even after the user has opened the door. In this position, the latch keeper poses a risk of an injury and can easily be damaged.
German Patent DE 10 2005 028 449 B4 describes a dishwasher in which the latch keeper can be moved to three different positions by an electric motor. The first position is the initial position of the latch keeper, in which the door is fully closed to enable a washing operation to be performed. At the end of the cycle, the latch keeper is moved from said first position to a second position wherein the door is ajar, leaving a relatively large gap. This assists in the drying process. After the door is opened, the latch keeper is retracted to a third position. In this position, the latch keeper projects from the housing only to such an extent that the door will remain in an only slightly ajar position upon closure. In this position, there is a reduced risk of injury. In addition, automatic retraction of the latch keeper to the first position assists the user in closing the door, since he or she no longer has to push against the force of the door seal.
In the dishwashers described above, an electric gear motor is used as the actuator. This motor is expensive and susceptible to wear. In addition, two position switches are employed.